Hydrometer



Dec. 23, 1941. c. E. LINEBARGER HYDROMETER Original Filed Jan. 9, 1937 2Sheets-Sheet 1 Dec. 23, 1941- c. E. LINEBARGER HYDROMETER 2 Sheeis-Sheet2 Griginal Filed Jan. 9, 1937 m. E .e

Patented Dec. 23, 1941 HYDROMETER Charles E. Linebarger, deceased, lateoi Chicago, Ill., by Charles E. Linebarger, Jr., administrator, Chicago,lll., assignor to The Chaslyn Company, Chicago, Ill., a corporation ofIllinois Original application January 9, 1937, Serial No. 119,735.Divided and this application January 7, 1939, Serial No. 249,742

4 Claims.

This invention relates to hydrometers, and particularly to hydrometerswhich are designed to very accurately indicate the density of the liquidinvolved independently of temperature changes. In a copending patentapplication, Serial No. 55,765, filed December 23, 1935, there aredescribed some uses thermostats applied to therotating elemen.'l ofhydrostatic vanes for the purpose of correcting their density readingsfor changes of temperature. In the present application there are givenadditional means to bring about such corrections, incorporated not onlyin the movable vane or hand or dial, but also in the scale sheet, assuch, and other means, being applicable also to different kinds ofhydrometers, as, for instance, constant weight float hydrometers.

One object of the present invention ls to provide apparatus mountedwithin the bulb or barrel of a constant weight float hydrometer by meansof which the scale sheet is shifted to and fro so as to bring itsreadings in accord with those corrected for temperature variations. Asecond object of the invention is to t thermostatic means to hydrometervanes whereby the scale sheets are moved to change the densityindications, when the liquids under test are heated, by amountscommensurate with their changes in density owing to the changes intemperature.

A third object is to introduce mechanical means into a hydrometricassembly between the scale and the thermostat, so as to convert theuniform thermostatic motion into an irregular motion designed to matchthe irregular change in density of a liquid owing to its change intemperature. Other objects of the invention will be apparent from aconsideration of the drawings herewith and the following descriptionsthereof.

This application is a division of copending patent application SerialNo. 119,735, filed January 9, 1937, which maturedinto Patent Number2,185,205 January 2, 1940, and reference may be had to that patent inregard to further details relating to the objects and apparatus of theinvention.

f the accompanying drawings, Fig. 1 is an elevation of a constant weighthydrometer which embodies some of the features of this invention; Fig. 2is an enlarged sectional view along the line 2-2 of Fig. 1; Fig. 3 toFig. 7 illustrate by similar views modicatlons of the hydrometerillustrated in Fig. 1.

Fig. 1 illustrates a hydrometer of the constant weight barrel or bulbtype. This comprisesa glass tube or barrel I0 with an elongated stem orneck I I, which is completely sealed and encloses in its lower end anysuitable ballast, such as the shot I2. In this case the shot ispreferably held in place by means of the wax I3. Within the tube isfixed a support I4, which in this instance is anchored in the wax I3'.The upper end of the arm of the support I4 has xed to it a bi-metal coilI5 which has an outwardly extending arm I6. Also anchored in the wax isa frame Il which has formed therein a slot I8. 'Ihe outer end of the armI6 carries a block 20 which has therein a slot 2|. In this slot plays apin 22 free to move therein longitudinally. The pin also plays freely inthe slot I8. 'Ihis latter slot has one portion at least which isnonconcentric with reference to the center of the coil I5. The pin 22has pivoted thereto the lower end of a link 23 which carries a scale 24by means of the lever 25 and the link 26. The fulcrum of the lever ispivotally attached to the frame I1.

The purpose of this slot structure is to compensate for any variationsin the scale movement from the density changes of the liquid beingtested owing to temperature changes thereof.

In operation, as the temperature of the liquid increases above normal,the outer end of the arm I6 will rise by virtue of the action of theunlike metals of the bimetal coil I5. This will elevate the scale. Atthe same time owing to the decreased density of the liquid thehydrometer will sink. hence, Without compensating for the change intemperature the reading of the hydrometer for normal temperatures wouldbe incorrect. But as the hydrometer sinks the scale will be elevated bythe-coil, and this will compensate generally for the temperature change.

With the slot arrangement described compensation is not only providedfor the temperature changes but also for any irregularities in the rateof change of the density with reference to the temperature change. Atcertain temperatures the density may vary at a greater rate with a giventemperature change than at other temperatures. This is compensated forby the slot arrangement. As the outer end of the arm I6 rises owing tothe increasing temperature the scale sheet will be elevated, but theupward movement of the scale sheet will not correspond with theexpansion of the liquid in some cases. But by having the slot I8nonconcentric with reference to the center of the bimetal coil themovement ot the scale may be made to vary from the rate of movement o!the pin 22 by which it is operated. If the nature of the liquid under 55test is such that its density decreases at a greater rate than thetemperature increase the radius of curvature of the slot may beincreased as it passes upwardly so as to force the pin outwardly fromthe center of the coil and increase the rate at which the scale iselevated.

Also the shape of the slot may be made to compensate for the variationin rate of movement of the scale owing to the movement of the arm endand the lever end. As they move upwardly from the positions shown in thedrawings the vertical movement rate decreases, thus decreasing the rateof upward movement of the scale. Again by. increasing the radius of thecurvature of the slot this decrease in the movement of the scale can becompensated for. By properly shaping the slot the indications of thescale may be compensated for for any peculiarity of the liquid or themechanism.

Figs. 3 and 4 illustrate further use of the bimetal element for makingcorrections of the scale movement or readings. In this case the bimetalcoil 30 is fixed to the arm 3| which in turn is fixed to a pedestal 32anchored in the ballast 33. The outer end of the arm 34 of the coil ispivoted to a link 35, the upper end of which is pivoted to a lever 36which operates the scale 31 by means of a link 38. The lever 36, ispivoted to another arm 40 of the pedestal 32, and the link 4l, whichconnects the link 38 with the scale 31, is guided by an extension 421 ofthe arm 40.

As the expansion of the liquid under test, owing to its increasedtemperature, allows the hydrometer to sink more in the liquid, theunwinding of the coil, owing to its increased temperature, will causethe scale to be elevated with reference to the stem 43, so as tocompensate, so far as the density readings are concerned, for thesinking of the hydrometer in the liquid because of its decreaseddensity. As will be readily understood, the scale is elevated in thestem. 43 by means of the action of the lever and the links, as the coil30 unwinds.

Also, it is to be understood that in these various modifications theleverage may be increased by additional levers, or by other methods ofincreasing or magnifying the movements of the scale or the effectivemovements of the outer end of the arm of the bimetal coil. Also it is tobe understood that Fig. 4 is merely a view of Fig. 3 rotated through 90.

Figs. and 6 illustrate a further modification in which the bimetal coil44 is used, Fig. 6 being a view along the line 6-6 of Fig. 5. In thiscase the support 45 for the coil is held in place in the barrel by theprotrusions 46 formed in the wall of the barrel. The frame which formsthe support 45 is composed of elastic material and is triangular shapedand each corner projects into a protrusion 46. In order that the framemay be assembled in the barrel, the arms 41 and 48 are disconnected andlap on each other so that the arms may be sprung together suflciently toallow the corners 50 to be slipped into their protrusions. When the armsare released the frame will spring in place and will be firmly held bythe protrusions. An arm 5I, projecting inwardly and downwardly from thearm 48, serves to throv7 the coil free from the barrel wall and theframe.

The outer end of the arm 52 of the coil is pivoted to the lower end of alink 53, which in turn carries the scale 54. In this case no means areshown to .compensate for any irregularities in movement or expansion ofthe liquid; but obviously those described elsewhere could be applied tothis modication, and additional leverage also could be applied.

Fig. 'I illustrates a somewhat similar arrangement. The coil 66 isbimetalllc and operates the scale 51 by means oi' a link '53, a lever 6land a link 6|. The link 62 which connects the link 6I and the scale isguided by a cross bar 63. In

lower end of the stem is pressed into and sealed in the upper end of themember 66, and the lower end of the member 66 is pressed into and sealedin the upper end of the barrel. The stem may be made of any transparentmaterial, such as ordinary glass or glass constructed from organicmaterial, so-called organic or synthetic glass. The member 66 and thebarrel may be made of any suitable material, such as metal or glass orsome plastic material. The stem, which is necessarily transparent, ispreferably formed of methyl methacrylate resin plastics or those havingsimilar characteristics. Since, in the case of the constant 'weightfloat hydrometers the thermostats and the metal parts connecting them tothe scales are enclosed, and are thus protected against any possibilityof corrosive action, these parts may be composed of any ordinarymaterial, such as tinned iron or the like.

In this case, also,` the ballast end is fastened in the lower end of thebarrel, being preferably threaded therein. This end may be made of anyplastic material which is suitable, or it may be made of materialsufficiently dense to provide for the ballasting of the hydrometer.Preferably, the metal tip 68 is used, which is of sumcient weight toproperly sink and hold the hydrometer in the liquid to be tested. With atip of this nature, the desired weight of the hydrometer may beaccurately obtained by illing off a portion of the tip, which isintentionally initially made somewhat too heavy. This same method ofadjusting the hydrometer weight may be used in case of the hydrometerssuch as those illustrated in Figs. 3 and 4. In such cases the pedestal32 is not'only anchored in the plastic material 33 but it also projectsout through the lower end thereof and this projecting tip 10 may befiled or ground off somewhat to reduce the Weight of the apparatus asdesired for calibration.

The materials of which the laminations of the bimetal element arecomposed have not been shown in the drawings; but in some cases thecomposition of the laminations becomes important. These bimetal coilsmay be made of various materials so as to vary materially the deflectionconstants; and also so that the deflection constant will vary withvarying temperatures. In their use with the invention it is preferred toprovide laminations which will give deflection constants correspondingto the coeilicient of expansion of the liquid to be tested, and in somecases, if the coeiiicient varies somewhat with the temperature, bimetalcoils can be provided which will give varying movements correspondingwith the varying coefficients. In such cases the compensating meansherein described to correct for irregularities are unnecessary, exceptthey may be desirable to correct for irregularities in the action of themechanism itself.

In cases where the thermostatic members of hydrometers may come incontact with corrosive liquids, means are applied to prevent anychemical actionupon the materials. Electroplating the metals of thebimetal elements with cadmium or tin, preferably with a coat of each atleast 0.005 inch thick prevents corrosion except in cases of strongsolutions of acids or alkalies. For these may be used laminated metalsrolled out of thin sheets oi' gold, or other suitable inert material,covering a thick sheet of base metal, any edges exposed by the cuttingof the edges of the metal combination being electroplated with the inertmaterial.

I claim as his invention: v

1. A hydrometer comprising a sealed tube, a scale movably mounted in thetube and adapted to indicate the depth to which the tube sinks whenimmersed in a liquid the density of which is to be tested, meansresponsive to temperature variations of the liquid, xed with referenceto the tube and operatively connected with the scale, and comprising abi-metal coil having a projecting arm, and means operatively connectingthe arm with the scale, comprising a lever, a fulcrum connection betweenone end of said lever and a part xed to the tube, a link connecting thefree end of the lever to the scale, and a link connecting the arm of thebi-metal coil to the lever at a point between the fulcrum and the firstmentioned link, whereby movements of the arm of the bi-metal coil arecommunicated in multiplied amount to the scale, substantially asdescribed.

2. A hydrometer comprising a sealed tube, a scale movably mounted in thetube and adapted to indicate the depth to which the tube sinks whenimmersed in a liquid the density of which is to be tested, meansresponsive to temperature variations o! the liquid, xed with referenceto link with one end slidably connected to both slots and the other endoperatively connected to the scale, substantially-as described.

3. A hydrometer comprising a sealed tube, a scale movably mounted in thetube and adapted to indicate the depth to which the tube sinks whenimmersed in a liquid the density of which is to be tested, meansresponsive to temperature variations of the liquid, fixed with referenceto the tube and operatively connected with the scale, comprising abi-metal coil having a projecting arm, and means operatively connectingthe arm with the scale, comprising a lever, a fulcrum connection betweensaid lever and a part xed to the tube, and link connections between thelever and the scale, and also between the lever and the arm, said partxed to the tube including a stem extending through the tube to theexterior thereof, substantially as described.

4. A hydrometer comprising a sealed tube, a scale movably mounted in thetube and adapted to indicate the depth to which the tube sinks whenimmersed .in a liquid the density. of which is to be tested, meansresponsive to temperature variations of the liquid, flxed with referenceto the tube and operatively connected with the scale, comprising abi-metal coil having a projecting arm, and means operatively connectingthe arm with the scale, comprising a lever, a fulcrum connection betweensaid lever and a part iixed to the tube, and link connections betweenthe lever able iulcrum as aforesaid, substantially as de- Adnanistratorscribed.

' CHARLES E. LINEBARGER, JR.,

of the Estate ol Charles E. Linebarger, Deceased.

